Cycles of Matter and Life on Earth

The video tutorial explores the cycles that sustain life on Earth, focusing on the carbon, nitrogen, phosphorus, and water cycles. It explains how these elements and compounds move through Earth's spheres, highlighting their roles in both living and non-living systems. The tutorial emphasizes Earth's closed system, where matter changes form but is not lost. Each cycle is detailed, showing how elements circulate and support life. The video concludes with a recap of the cycles' importance to Earth's biosphere.

What does it mean when we say Earth is a closed system?

• The system is open to the universe.

• Materials can enter and leave the system freely.

• The system is isolated from all forms of energy.

• Materials cycle within the system but do not leave it.

Which of the following is a compound rather than an element?

• Water

• Carbon

• Nitrogen

• Phosphorus

What process releases carbon dioxide into the atmosphere from burning fuels?

• Respiration

• Photosynthesis

• Combustion

• Decomposition

How do plants contribute to the carbon cycle?

• By decomposing carbon into the soil

• By converting carbon dioxide into nitrogen

• By absorbing carbon dioxide during photosynthesis

• By releasing carbon dioxide during photosynthesis

What is the first stage of the nitrogen cycle?

• Fixation

• Denitrification

• Nitrification

• Immobilization

Which process in the nitrogen cycle converts nitrogen gas into a form usable by plants?

• Mineralization

• Fixation

• Denitrification

• Nitrification

Why doesn't the phosphorus cycle involve the atmosphere much?

• Phosphorus is only found in water.

• Phosphorus is only absorbed by animals.

• Phosphorus does not enter the gaseous state.

• Phosphorus is not found in rocks.

What is the process called when water vapor turns into liquid droplets?

• Evaporation

• Precipitation

• Collection

• Condensation

In the water cycle, what is the term for water falling from clouds as rain or snow?

• Collection

• Evaporation

• Precipitation

• Condensation

What happens to phosphorus when plants and animals die?

• It evaporates into the atmosphere.

• It returns to the soil and water.

• It is absorbed by the atmosphere.

• It turns into nitrogen.